A conveyance such as a vehicle may have a head-up display device capable of projecting information to the front side of an occupant. The occupant can obtain the information by visually recognizing a virtual image projected to the front side. The technique disclosed in PTL 1 is related art concerning a head-up display device.
A head-up display device as described in PTL 1 includes a first display for displaying a first image, a second display for displaying a second image, a half mirror through which light from the first display passes and which reflects light from the second display, and a front glass (projection surface) onto which light having passed through or being reflected by the half mirror is projected.
As for the lengths of optical paths through which light passes, the length of the optical path from the first display to the front glass is longer than the length of the optical path from the second display to the front glass. This causes the occupant to recognize the first image and the second image closer to the first image. That is, it is possible to generate a sense of depth in a virtual image by projecting the images having different lengths of the optical paths onto the front glass.
However, the head-up display device as described above needs to have two displays for emitting two different types of images. Accordingly, the cost of components becomes high and the device size becomes large.